With rapid development of a mobile terminal technology, a mobile terminal device such as a mobile phone or a tablet computer generally has multiple wireless communication capabilities such as cellular communication, Wireless Fidelity (WiFi) communication, and Bluetooth communication. Therefore, multiple antennas or an antenna with multiple resonance frequencies needs to be configured for the mobile terminal device, so as to cover multiple frequency bands for wireless communication.
Currently, to meet a requirement of people for a simple and thin appearance of a mobile terminal device, an antenna of the mobile terminal device is generally disposed inside the device, and a plastic housing is generally used, for example, a housing with polycarbonate (PC) plastic and acrylonitrile butadiene styrene (ABS) plastic. However, because a metal housing is not only fashionable and textured, but also has excellent features such as better durability, a good heat-conducting property, and a long life span, people tend to purchase a mobile terminal device with a metal housing and a metal frame. Therefore, the mobile terminal device with a metal housing and a metal frame is more popular.
However, under a design trend towards a simple and thin mobile terminal device, net space that can be used by an antenna is increasingly limited, and an operating environment of the antenna becomes worse. In addition, a metal housing and a metal frame of the mobile terminal device shield an electromagnetic wave transmitted or received by the antenna in the mobile terminal device. Consequently, communication performance of the mobile terminal device is affected, and antenna utilization is low.